CHAOTIC PARTICLE DYNAMICS IN VISCOUS FLOWS - THE 3-PARTICLE STOKESLETPROBLEM

It is well known, that the dynamics of small particles moving in a vis cous fluid is strongly influenced by the long-range hydrodynamical int eraction between them. Motion at high viscosity is usually treated by means of the Stokes equations, which are linear and instantaneous. Nev ertheless, the hydrodynamical interaction mediated by the liquid is no nlinear; therefore the dynamics of more than two particles can be rath er complex. Here we present a high resolution numerical analysis of th e classical three-particle Stokeslet problem in a vertical plane. We s how that a chaotic saddle in the phase space is responsible for the ex treme sensitivity to initial configurations, which has been mentioned several times in the literature without an explanation. A detailed ana lysis of the transiently chaotic dynamics and the underlying fractal p atterns is given.